The class of polymers of carbon monoxide and olefins has been known for a number of years. Brubaker, U.S. Pat. No. 2,495,286 produced such polymers of relatively low carbon monoxide content in the presence of free radical catalysts, e.g., peroxy compounds. U.K. No. 1,081,304 produced similar polymers of higher carbon monoxide content in the presence of alkylphosphine complexes of palladium salts as catalyst. Nozaki extended this process through the use of a number of arylphosphine complexes of palladium salts and certain inert solvents. See, for example, U.S. Pat. No. 3,694,412.
More recently, the class oi linear alternating polymers of carbon monoxide and at least one ethylenically unsaturated hydrocarbon, e.g., ethylene or ethylene and propylene, has become of greater interest in part because of the greater availability of these polymers. The polymers, generally known as polyketones, have a highly regular linear alternating structure of the formula --CO--A-- wherein A is the moiety of the ethylenically unsaturated hydrocarbon polymerized through the ethylenic unsaturation. The general process for the production of such polymers is illustrated by a number of published European Patent Application Nos. including 0,121,965 and 0,181,014. The process typically involves a catalyst composition formed from a compound of the Group VIII metals palladium, cobalt or nickel, the anion of a non-hydrohalogenic acid having a pKa less than 2 and a bidentate ligand of phosphorus, arsenic or antimony.
When the polymer is a copolymer oi ethylene and carbon monoxide, the polymer chain is represented by repeating units of the formula EQU --CO--CH.sub.2 --CH.sub.2 --. I
The end groups or "caps" of the polymer chain will depend on what materials are present during the production of the polymer and whether and how the polymer was purified. The overall properties of the polymer are not greatly influenced by the nature of the end groups and the polymer is fairly represented by the polymer chain depicted above.
The polymer properties are greatly influenced by the molecular purity of the polymer which is herein intended to mean the extent to which the polymer consists of repeating units of the above formula I. It will be appreciated that the polymer of the above formula I is a polymer of carbon monoxide and ethylene in equimolar (as well as equal weight) quantities. Thus, a polymer of substantially lower carbon monoxide content cannot have a high molecular purity in terms of a single reoccurring unit. Alternatively, a polymer made by a relatively energetic means, e.g., by irradiation or by free radical catalysis, will not typically have a regular reoccurring structure even through the polymer may have carbon monoxide and ethylene present in a 1:1 molar ratio.
When copolymers of carbon monoxide and ethylene of low molecular purity are subjected to hydrogenation, either catalytic or stoichiometric, the resulting polymer is of generally less desirable properties due in part to the absence of crystallinity. For example, Scott, U.S. Pat. No. 2,495,292, reduces a polymer apparently similar to that of Brubaker over a nickel catalyst to obtain a pliable, rubbery material. Although the reduced polymer of Scott had a polyol content, there were unreacted carbonyl groups present. A similar polyol of unspecified properties produced by heterogeneous hydrogenation of a nonalternating polyketone is shown by Morishima et al, European Polymer Journal, Vol. 9, pp. 669-675 (1973).
A number of polyalcohol polymers are available which can be depicted as polymers of ethylene and the non-isolable vinyl alcohol. Because in part of a high molecular purity, these polymers have a number of desirable properties. The method of producing such polymeric polyalcohols causes the alcohols to be somewhat expensive. It would be of advantage to produce polymeric polyalcohols of good properties from copolymers of carbon monoxide and ethylene.